Since the new_metric and last_hop_metric variables can reach the MAX_METRIC(0xffffffff) value, an integer overflow may occur when multiplying them by 10/9. It can lead to incorrect behavior.

Found by InfoTeCS on behalf of Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: a8d418d9ac25 ("mac80211: mesh: only switch path when new metric is at least 10% better") Cc: stable@vger.kernel.org Signed-off-by: Ilia Gavrilov Ilia.Gavrilov@infotecs.ru --- net/mac80211/mesh_hwmp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c index 4e9546e998b6..7d367ff1efc2 100644 --- a/net/mac80211/mesh_hwmp.c +++ b/net/mac80211/mesh_hwmp.c @@ -458,7 +458,7 @@ static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata, (mpath->sn == orig_sn && (rcu_access_pointer(mpath->next_hop) != sta ? - mult_frac(new_metric, 10, 9) : + mult_frac((u64)new_metric, 10, 9) : new_metric) >= mpath->metric)) { process = false; fresh_info = false; @@ -533,7 +533,7 @@ static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata, if ((mpath->flags & MESH_PATH_FIXED) || ((mpath->flags & MESH_PATH_ACTIVE) && ((rcu_access_pointer(mpath->next_hop) != sta ? - mult_frac(last_hop_metric, 10, 9) : + mult_frac((u64)last_hop_metric, 10, 9) : last_hop_metric) > mpath->metric))) fresh_info = false; } else {